DESIGN OF THE PRIMARY BEAMS Determine a suitable size for the primary beams, using WB sections Grade 300 steel. Note the following: A 120mm-thick reinforced concrete slab will be cast on top of the primary beams as depicted. This slab will be 'locked' down onto the tops of the beams by the provision of shear connectors which will be welded onto the tops of the beams and cast into the slabs. The shear connectors will restrain any possible lateral buckling of the beam top flange wherever the slabs are located. Allow for a live loading on the slabs of 2 kN/m2. The slabs will be supported by additional steelwork not shown on the diagram and not relevant to this exercise. Assume the cross-section of the primary beams at both ends is fully (F) restrained. Use the same deflection limitation as specified for the secondary beams, but only the deflection due to the beam self-weight and crane need to be considered (i.e. the additional small deflection due to the slab loading may be neglected). The shear capacity of the primary beams should be checked. The web bearing capacity of the primary beams should be checked at